fix(opensearchservice): IM4GN instances don't support EBS (#27765)

Relevant docs https://aws.amazon.com/opensearch-service/pricing/

Closes #27757.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: msambol

packages/aws-cdk-lib/aws-opensearchservice/lib/domain.ts

@@ -1525,8 +1525,8 @@ export class Domain extends DomainBase implements IDomain, ec2.IConnectable {
 
     // Validate against instance type restrictions, per
     // https://docs.aws.amazon.com/opensearch-service/latest/developerguide/supported-instance-types.html
-    if (isSomeInstanceType('i3', 'r6gd') && ebsEnabled) {
-      throw new Error('I3 and R6GD instance types do not support EBS storage volumes.');
+    if (isSomeInstanceType('i3', 'r6gd', 'im4gn') && ebsEnabled) {
+      throw new Error('I3, R6GD, and IM4GN instance types do not support EBS storage volumes.');
     }
 
     if (isSomeInstanceType('m3', 'r3', 't2') && encryptionAtRestEnabled) {
@@ -1541,10 +1541,10 @@ export class Domain extends DomainBase implements IDomain, ec2.IConnectable {
       throw new Error('T2 and T3 instance types do not support UltraWarm storage.');
     }
 
-    // Only R3, I3 and r6gd support instance storage, per
+    // Only R3, I3, R6GD, and IM4GN support instance storage, per
     // https://aws.amazon.com/opensearch-service/pricing/
-    if (!ebsEnabled && !isEveryDatanodeInstanceType('r3', 'i3', 'r6gd')) {
-      throw new Error('EBS volumes are required when using instance types other than r3, i3 or r6gd.');
+    if (!ebsEnabled && !isEveryDatanodeInstanceType('r3', 'i3', 'r6gd', 'im4gn')) {
+      throw new Error('EBS volumes are required when using instance types other than R3, I3, R6GD, or IM4GN.');
     }
 
     // Only for a valid ebs volume configuration, per

packages/aws-cdk-lib/aws-opensearchservice/test/domain.test.ts

@@ -1809,8 +1809,8 @@ each(testedOpenSearchVersions).describe('custom error responses', (engineVersion
     })).toThrow(/Node-to-node encryption requires Elasticsearch version 6.0 or later or OpenSearch version 1.0 or later/);
   });
 
-  test('error when i3 or r6g instance types are specified with EBS enabled', () => {
-    expect(() => new Domain(stack, 'Domain1', {
+  test('error when I3, R6GD, and IM4GN instance types are specified with EBS enabled', () => {
+    expect(() => new Domain(stack, 'Domain2', {
       version: engineVersion,
       capacity: {
         dataNodeInstanceType: 'i3.2xlarge.search',
@@ -1819,8 +1819,8 @@ each(testedOpenSearchVersions).describe('custom error responses', (engineVersion
         volumeSize: 100,
         volumeType: EbsDeviceVolumeType.GENERAL_PURPOSE_SSD,
       },
-    })).toThrow(/I3 and R6GD instance types do not support EBS storage volumes/);
-    expect(() => new Domain(stack, 'Domain2', {
+    })).toThrow(/I3, R6GD, and IM4GN instance types do not support EBS storage volumes./);
+    expect(() => new Domain(stack, 'Domain3', {
       version: engineVersion,
       capacity: {
         dataNodeInstanceType: 'r6gd.large.search',
@@ -1829,7 +1829,17 @@ each(testedOpenSearchVersions).describe('custom error responses', (engineVersion
         volumeSize: 100,
         volumeType: EbsDeviceVolumeType.GENERAL_PURPOSE_SSD,
       },
-    })).toThrow(/I3 and R6GD instance types do not support EBS storage volumes/);
+    })).toThrow(/I3, R6GD, and IM4GN instance types do not support EBS storage volumes./);
+    expect(() => new Domain(stack, 'Domain4', {
+      version: engineVersion,
+      capacity: {
+        dataNodeInstanceType: 'im4gn.2xlarge.search',
+      },
+      ebs: {
+        volumeSize: 100,
+        volumeType: EbsDeviceVolumeType.GENERAL_PURPOSE_SSD,
+      },
+    })).toThrow(/I3, R6GD, and IM4GN instance types do not support EBS storage volumes./);
   });
 
   test('error when m3, r3, or t2 instance types are specified with encryption at rest enabled', () => {
@@ -1872,7 +1882,7 @@ each(testedOpenSearchVersions).describe('custom error responses', (engineVersion
     })).toThrow(/t2.micro.search instance type supports only Elasticsearch versions 1.5 and 2.3/);
   });
 
-  test('error when any instance type other than R3, I3 and R6GD are specified without EBS enabled', () => {
+  test('error when any instance type other than R3, I3, R6GD, or IM4GN are specified without EBS enabled', () => {
     expect(() => new Domain(stack, 'Domain1', {
       version: engineVersion,
       ebs: {
@@ -1881,16 +1891,16 @@ each(testedOpenSearchVersions).describe('custom error responses', (engineVersion
       capacity: {
         masterNodeInstanceType: 'm5.large.search',
       },
-    })).toThrow(/EBS volumes are required when using instance types other than r3, i3 or r6gd/);
+    })).toThrow(/EBS volumes are required when using instance types other than R3, I3, R6GD, or IM4GN./);
     expect(() => new Domain(stack, 'Domain2', {
       version: engineVersion,
       ebs: {
         enabled: false,
       },
       capacity: {
-        dataNodeInstanceType: 'm5.large.search',
+        dataNodeInstanceType: 'r5.large.search',
       },
-    })).toThrow(/EBS volumes are required when using instance types other than r3, i3 or r6gd/);
+    })).toThrow(/EBS volumes are required when using instance types other than R3, I3, R6GD, or IM4GN./);
   });
 
   test('can use compatible master instance types that does not have local storage when data node type is i3 or r6gd', () => {